Electromigration in line-type Cu/Sn-Bi/Cu solder joints

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Detail(s)

Original languageEnglish
Pages (from-to)1721-1726
Journal / PublicationJournal of Electronic Materials
Volume37
Issue number11
Publication statusPublished - Nov 2008

Abstract

In this study, the different electromigration (EM) behaviors of eutectic Sn-Bi solder in the solid and molten states were clarified using line-type Cu/Sn-Bi/Cu solder joints. When the eutectic Sn-Bi solder was in the solid state during the EM test, a Bi-rich layer formed at the anode side while a Sn-rich band formed at the cathode side, and the intermetallic compound (IMC) at the cathode side was thicker than that at the anode side. The growth of the Bi-rich layer exhibited a linear dependence on the time of stressing. While the actual temperature of the solder joint increased to 140°C and the solder was in a molten state or partially molten state, two separate Bi-rich layers formed at the anode side and a great many Cu 6Sn 5 IMC precipitates formed between the two Bi-rich layers. Also, the IMC layer at the cathode side was thinner than that at the anode side. With a current-crowding-reduced structure, the products of diffusivity and effective charge number of Bi in the eutectic Cu/Sn-Bi/Cu solder joints stressed with current density of 5 × 10 3 A/cm 2 at 35°C, 55°C, and 75°C were calculated. © 2008 TMS.

Research Area(s)

  • Electromigration, Line-type Cu/Sn-Bi/Cu solder joints, Microstructure

Citation Format(s)

Electromigration in line-type Cu/Sn-Bi/Cu solder joints. / Gu, X.; Chan, Y. C.
In: Journal of Electronic Materials, Vol. 37, No. 11, 11.2008, p. 1721-1726.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review